Professor DeJong’s research focuses on a suite of topics related to the interaction of soil with various processes including biological activity, structural element interfaces, and in situ probes and sensors. Previous research topics include the role of surface hardness and roughness on soil-structure interface behavior, stratigraphic layer detection using a miniature piezoprobe, and the influence of pile texturing on axial capacity. He has received research funding from the National Science Foundation, Massachusetts Highway Department, Geokon, Inc., Australian Research Council, and the Massachusetts Technology Consortium. He is on the editorial board of the ASTM Geotechnical Testing Journal, and is a member of a number of national committees related to his areas of expertise.